Teagasc is urging all Irish potato growers to immediately overhaul their potato blight spraying programs due to the increasing presence of resistant blight populations in Ireland and across Europe.
“The era of block spraying for blight is over,” emphasized Teagasc potato specialist Dr. Steven Kildea at a blight workshop in Co. Down this week. The event was organized by the College of Agriculture, Food and Rural Enterprise (CAFRE) in collaboration with Teagasc.
“The future will focus on a strategy of mixing two different blight chemistries in one tank and ensuring that modes of action are rotated in sequential spray applications,” Kildea stated.
He confirmed that blight populations are evolving faster than ever, with resistance to available fungicides becoming a significant concern for the potato industry in Ireland and Europe.
Compounding industry worries is the removal of several blight products from the market in recent years.
“It is now essential to use the remaining fungicide chemistries most effectively while minimizing the risk of further mutations among blight populations,” Kildea explained.
“This is why potato growers must avoid sequential use of the same blight chemistries. Mixing and alternating is the way forward, requiring the full use of all currently available blight chemistries,” he added.
The Teagasc representative acknowledged that the new blight control approach will significantly increase costs for potato growers.
“But it’s a price worth paying,” he said. “The alternative is substantial blight damage to potato crops now and in the future.”
“In truth, we have been fortunate in maintaining the efficacy of many blight prevention chemistries with single product applications up to this point.”
Kildea also highlighted integrated pest management (IPM) options available to potato growers, such as avoiding planting potatoes in areas most prone to blight.
“Why plant potatoes under trees or near telegraph poles? Tree cover promotes conditions favorable to blight, and crops near obstacles like telegraph poles are challenging to spray effectively,” he said.
“We have the means to control the various blight strains affecting potato crops. But achieving this will require growers to fundamentally change their blight spraying programs. And the clock is ticking,” Kildea concluded.
